The new BMW X6 SUV has been spotted testing in Europe ahead of going on sale in the UK at the end of this year. The car is expected to have its public debut at the Moscow motor show in August.

Having been previously spotted testing at the Nürburgring, this latest test mule sports less camouflage than previous models. In particular, new tail lights can be seen on this model, sporting new rear light designs.

As well as a more muscular appearance than the current model, which moves away from the X5 in terms of shape and detail, we can also see the new X6 has grown considerably in size, to around 4910mm long. That should give the new X6 more interior space than the current model, which offers 570 litres of storage with the rear seats up, rising to 1450 litres with them down.

Power for the new car is likely to come from a new range of twin-scroll turbocharged 3.0-litre diesel and tri-turbocharged 3.0-litre six-cylinder engines, as well as a selection of upgraded 4.4-litre V8 petrols for both standard and M division cars. A hybrid version, combining the 3.0-litre six-cylinder petrol with an electric motor, is also in development.

Based on a shortened version of the X5's platform, which is made largely of steel, the new X6 should weigh significantly less than the current model, which clocks in at 2145kg in standard form. As well as its lower weight, the new X6 will also use new axle assemblies, shared with the 5-series.

Elsewhere, the end of the year will also see the launch of the X6 M following the LA motor show, which adopts a more aggressive look than the standard car and will come with around 553bhp and 500lb ft of torque from its 4.4-litre turbocharged V8 engine.

The second-generaion X6 will act as a sister car to the latest X5, and forms part of an expanded SUV range which will also see the launch of a new X7, the largest SUV to be produced by the firm. That car will go into production at BMW's Spartanburg plant in North America in 2016. The new BMW X1 will also launch early in 2015, while the new X4 goes on sale in the UK in July.

One of the rivals to the new X6 will be the Mercedes MLC, which will be previewed by the Concept Coupe at the Beijing motor show later this month.